title: PIP5K-dependent production of PIP2 sustains microtubule organization to establish polarized transport in the Drosophila oocyte.
abstract: The attachment of the cytoskeleton to the plasma membrane is crucial in controlling the polarized transport of cell-fate-determining molecules. Attachment involves adaptor molecules, which have the capacity to bind to both the plasma membrane and elements of the cytoskeleton, such as microtubules and actin filaments. Using the Drosophila oocyte as a model system, we show that the type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K), Skittles, is necessary to sustain the organization of microtubules and actin cytoskeleton required for the asymmetric transport of oskar, bicoid and gurken mRNAs and thereby controls the establishment of cell polarity. We show that Skittles function is crucial to synthesize and maintain phosphatidylinositol 4,5 bisphosphate (PIP2) at the plasma membrane in the oocyte. Reduction of Skittles activity impairs activation at the plasma membrane of Moesin, a member of the ERM family known to link the plasma membrane to the actin-based cytoskeleton. Furthermore, we provide evidence that Skittles, by controlling the localization of Bazooka, Par-1 and Lgl, but not Lkb1, to the cell membrane, regulates PAR polarity proteins and the maintenance of specific cortical domains along the anteroposterior axis.
authors.affiliation: Institut Jacques Monod, Unité Mixte de Recherche 7592, CNRS, Universités Paris 7, 2 place Jussieu, F-75251, Paris Cedex 05, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Gervais
authors.forename: Sandra
authors.initials: S
authors.lastname: Claret
authors.forename: Jens
authors.initials: J
authors.lastname: Januschke
authors.forename: Siegfried
authors.initials: S
authors.lastname: Roth
authors.forename: Antoine
authors.initials: A
authors.lastname: Guichet
mesh_terms: D000199:Actins / Q000378:metabolism; D000483:Alleles; D000818:Animals; D001692:Biological Transport; D019521:Body Patterning; D002462:Cell Membrane / Q000201:enzymology; D002467:Cell Nucleus / Q000201:enzymology; D016764:Cell Polarity; D004331:Drosophila melanogaster / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D008840:Microfilament Proteins / Q000378:metabolism; D008870:Microtubules / Q000201:enzymology / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009865:Oocytes / Q000166:cytology* / Q000201:enzymology*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000096:biosynthesis*; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D034443:RNA Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D008840:Microfilament Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D012333:RNA, Messenger; C071058:moesin; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase